Mare Desiderii ("Sea of Dreams") was an area of the Moon named after Luna 3 returned the first pictures of the far side. This name is derived from the Russian Море Мечты, Mechta ("Dream") being the original name for the Luna 1 spacecraft.

This feature was later found to be composed of a smaller mare, Mare Ingenii (Sea of Ingenuity), and other dark craters. Today the IAU does not recognise the name Mare Desiderii.